21431232340 has 48 divisors (see below), whose sum is σ = 51557272704. Its totient is φ = 7330377600.

The previous prime is 21431232331. The next prime is 21431232371. The reversal of 21431232340 is 4323213412.

It is a super-2 number, since 2×21431232340² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122866 + ... + 240745.

It is an arithmetic number, because the mean of its divisors is an integer number (1074109848).

Almost surely, 2^21431232340 is an apocalyptic number.

21431232340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21431232340 is an abundant number, since it is smaller than the sum of its proper divisors (30126040364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21431232340 is a wasteful number, since it uses less digits than its factorization.

21431232340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364048 (or 364046 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 25.

Adding to 21431232340 its reverse (4323213412), we get a palindrome (25754445752).

The spelling of 21431232340 in words is "twenty-one billion, four hundred thirty-one million, two hundred thirty-two thousand, three hundred forty".